

# @hash = { 'k' => 'm', 'o' => 'q', 'e' => 'g' } 
$newstring=''


oldstring.each_byte {
 |x|
 if x<=96 && x>=123
	$newstring=(64).chr+$newstring 
 else
	$newstring=x.chr+$newstring 
 end
 }

p $newstring
